Some people like to do night shift, specifically request to do perm night, cos only need to work 3 or 4 days per week. However some don't, especially if its 3 rotating shifts, screw up your biological clock. I feel that perm night its still not so bad, worse combi is PM-AM shift, imagine leaving work at 9pm the day before then you need to report to work the next morning at 8am. Hence the turnover rate in hospital labs for med tech is high, cos of the rotating shift, fast paced environment and politics.